1. Field of the Invention
The present invention relates to a radiographic image reading device, a computer readable medium storing a radiographic image reading program, and a radiographic image reading method.
2. Description of the Related Art
When radiation (X-rays, α rays, β rays, γ rays, ultraviolet rays, an electron beam or the like) is irradiated onto a storage phosphor (a photostimulable phosphor), a portion of the radiation energy is stored in the storage phosphor. Subsequently, when an excitation light such as a laser light or the like is illuminated onto the storage phosphor, the storage phosphor is photostimulated and luminesces in accordance with the stored energy.
In general, radiographic image reading devices that employ storage phosphors are used for clinical applications, non-destructive testing in industry and the like. In a radiographic image reading device, image information of a radiographic image of an imaging subject, such as a weld or the like, is temporarily recorded in a sheet (an image plate IP, which is a storage phosphor sheet) that includes a storage phosphor layer. The storage phosphor sheet IP is scanned with excitation light, and photostimulated luminescence light that is produced is read photoelectrically.
For example, Japanese Patent Application Laid-Open (JP-A) No. 2004-163792 describes a radiographic image reading device that employs standard-resolution storage phosphor sheets and high-resolution storage phosphor sheets. When an image is being read at high resolution, a polygon mirror for illuminating the excitation light onto the surface of the storage phosphor sheet is rotated at a low speed, and when an image is being read at low resolution, the polygon mirror is rotated at a high speed.
Meanwhile, there are calls for the elimination of irregularities (scanning irregularities) that arise in radiographic images. JP-A No. 2010-239480 describes a technology that eliminates stripe irregularities (linear irregularities) in a radiographic image. This technology eliminates the linear irregularities by image correction from an original image that contains the linear irregularities, which has been read by a radiographic image reading device.
With the technology recited in JP-A No. 2010-239480, because irregularities are eliminated in the image data by the image correction, there is a risk that portions of a scanning target may be mistakenly removed. For example, in a case in which a portion of the scanning target is a fault in a weld or the like, due to the fault being linear, the fault may be treated as an irregularity and corrected.